2nd night with new CEM40, using KStars/Ekos. First night went OK, but tonight usb is not connecting more often than it is, and when it does connect it will not stay connected very long.
I started with the mount connected to the pi through a powered usb3 hub, based on having read about an incompatibility between the mount's usb and the pi (the same issue experienced by ASIAir users). My on-the-scope powered usb2 hub was also connected to that 2nd hub, then to the pi, and all the scope devices connected fine.
I so far have tried:A different usb cable from the usb hub to the mount.
Different ports on the usb hubA different powered usb hub (the one that always lives on the telescope connecting the cameras, etc to the pi. it has never given me a hint of trouble)
Directly from both usb3 and usb2 ports on the pi (that never worked in indoor testing, didn't work outside tonight, either)The usb-serial cable I always used with my CEM25P (that did not see the mount at all, but maybe I'm forgetting a driver or setting I need to make that work?)
I noticed some threads around different fora where people with the same raspberry pi (including ASIAir) - iOptron usb connection problem inserted an *un*powered hub between the pi and the mount. After digging through my computer junk drawers I found an old Amazon Basics unpowered 4-port usb2 hub, plugged that into a usb2 port on the pi and the mount (and only the mount) into one of the hub outputs. So far, it seems to work. I don't trust it enough to go to bed, so I only had about an hour to run it last night.
During the day today I powered up and ran a profile with only the mount attached and let it go for a few hours. It threw 3 "Read timeout" errors, but never disconnected. I did not send very many commands, just an occasional round of "clear parking data" / "set current as park position" / "write park data".
I would be a lot more likely to trust this to be a long-term fix if I knew much of anything about why the pi does not want to talk directly to the iOptron usb hub (the usb-in port on the mount must be itself a hub input).
I seem to recall some connection issues with the CEM40 which resolved after a firmware update. Just check that you are running the latest version of the mount firmware. Mine has not shown any connection issues since the update. I use a 7 port USB3 powered hub.
Hope this helps.
Ha Ha, you are right. First time I did it I thought I had bricked the mount as the connection dropped out half way through. However the last couple of times went without a hitch so hopefully this upgrading process is much more stable now. Fingers crossed
I have a GEM45 and was also having problems with dropping connections usually during a slew. I noticed that if I moved the USB cable it would sometimes loose connection. I narrowed it down to the USB B connection on the mount.
I made a modification to put a very secure 4 pin connector in parallel with the USB connector so I now have a totally stable connection. Since I was already busy I also replaced the power connecter with a solid 2 pin connector.
WO ZS 61
Edgehd 8 with Celestron OAG
Stellarmate on RPi 4
294 mc pro
224 planetary cam
174 guide cam
Sesto Senso focusser
QHY5II-Mono guide camera
EOS6D - not modified
The only firmware that was not up to date was the Main board. Updated that, Ekos still does not connect to the CEM40 directly from one of the pi usb2 ports.
I have had no dropped connections by going through the unpowered usb2 hub - yet (about 4 hours running simulators and 4 hours actual imaging). So it works, even if it requires a weird hack that I don't understand.
I just received CEM40 today. My rasberry pi4, too, does not recognize it. It says: [ERROR] Failed to connect to port (/dev/ttyUSB0). Error: Port failure Error: No such file or directory. Check if device is connected to this port.
P.S. My firmware version is: 210605. I think it's the newest.
This may not be the problem nor solution - I debugged this *endlessly* with my GEM45, and a powered hub didn't help (but I did spend money!).
See the culmination of my mostly-complete "saga"
The USB to RJ12 adapter however did *not* work, and the guiding issues were because I suck at polar alignment.
I did run into the "[ERROR] Failed to connect to port (/dev/ttyUSB0). Error: Port failure Error: No such file or directory. Check if device is connected to this port." problem as well - it was because the Pi couldn't assign it a USB adapter correctly, iirc because of the mount itself (was often the problem with the GEM45 when going direct-to-mount with the Pi).
You can see this on the Pi4 terminal by running:
Then plug in the mount however you are doing this via USB - you can see what that will likely look like
if you are experiencing the same problem I was.
TL;DR: Grab a cheap, *unpowered* USB hub (I linked directly to the one I ended up using) and try that - it may save you a massive amount of headache / money-spending. You can see in my other post(s) that I ended up getting a different USB cable as well, but that did not work by itself (it required the unpowered USB hub).
Last edit: 9 months 3 weeks ago by MH. Reason: Code blocks, please don't be mean to me